抄録
Attempts were devoted to use Streptomyces aureofaciens and Streptomyces erythreus, the antibiotics producers as sources for the biosynthesis of cobalamine. The constituents of the fermentation medium and the strain play an important role in the biosynthesis of vitamin B12. The same strain produced different amounts of antibiotic and vitamin on the two different constitutive media. The increase of the phosphorus concentration in the fermentation medium-within limits-increased the vitamin B12. The optimal concentration of phosphorus favourable for the synthesis of cobalamine was inhibitive for the antibiotic production. The phosphorus level in the fermentation medium plays an important role in the metabolism of carbohydrate and consequently on the biosynthesis of antibiotics. Low concentration of 5, 6-dimethylbenzimidazole (cobalamine precursor) in the presence of suitable phosphorus induced the microorganism to increase its biosynthetic potentiality for the vitamin B12 production.
